Fabrication and characterization of high-current-density carbon-nanotube cold cathodes

2005 ◽  
Vol 251 (1-4) ◽  
pp. 249-253 ◽  
Author(s):  
Chunhui Zhu ◽  
Chaogang Lou ◽  
Wei Lei ◽  
Xiaobing Zhang
Keyword(s):  
Carbon Nanotube ◽  
Current Density ◽  
High Current Density ◽  
High Current ◽  
Cold Cathodes ◽  
Fabrication And Characterization

Preparation and Characterization of CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA Bipolar Membrane Using Electrospinning Technique

2013 ◽  
Vol 774-776 ◽  
pp. 795-798
Author(s):  
Ting Jin Zhou ◽  
Min Lu ◽  
Ri Yao Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Splitting ◽  
Current Density ◽  
Voltage Drop ◽  
High Current Density ◽  
High Current ◽  
Bipolar Membrane ◽  
Electrospinning Technique ◽  
Exchange Layer

Carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA) and chitosan (CS)-polyvinyl alcohol were cross-linked by Fe3+and glutaraldehyde respectively to prepare cation exchange layer and anion exchange layer, and polyvinyl alcohol-sodium alginate (SA)-metal octocarboxyphthalocyanine (MePc (COOH)8, a kind of water splitting catalyst, here, Me stands for Fe3+or Co2+) nanofibers were prepared by electrospinning technique and introduced into the interlayer to obtain the CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA bipolar membrane (BPM). The experimental results showed that compared with the BPM without the PVA-SA-MePc (COOH)8interlayer, the water splitting efficiency at the interlayer of the CMC-PVA/PVA-SA-MePc (COOH)8/ CS-PVA BPM was obviously increased, and its membrane impedance decreased. When the concentration of FePc (COOH)8in the PVA-SA-FePc (COOH)8nanofibers was 3.0%, the trans-membrane voltage drop (IRdrop) of the CMC-PVA/PVA-SA-FePc (COOH)8/CS-PVA BPM was as low as 0.6V at a high current density of 90 mA/cm2.

Experimental Study of Damage Mechanism of Carbon Nanotube as Nano-Component of Electronic Devices Under High Current Density

2013 ◽  
Author(s):  
Kazuhiko Sasagawa ◽  
Kazuhiro Fujisaki ◽  
Jun Unuma ◽  
Ryota Azuma
Keyword(s):  
Carbon Nanotube ◽  
Current Density ◽  
High Current Density ◽  
Electronic Devices ◽  
Damage Mechanism ◽  
Cathode Side ◽  
Testing System ◽  
High Current ◽  
Lower Oxygen ◽  
Microscopic Studies

Carbon nanotube (CNT) has a great tolerance to high current density which is a cause of electromigration (EM). Therefore, CNT is expected to use as the materials of nanoscale components of electronic devices. The damage mechanisms of CNT are regarded as the effects of oxidation by Joule heating and/or the EM by high-density electron flows. In this study, we investigated the damage mechanism of CNT structures used as nano-component of electronic devices. An EM acceleration testing system was designed using the CNT structures collected at the gap of thin-film electrodes. The EM tests were conducted under the several kinds of current density conditions and the surrounding environments. An indicator of lifetime was determined by voltage measurements during the acceleration tests and their fracture phenomena were evaluated by means of microscopic observations. As the results, the amounts of lifetime of CNT were longer in the lower oxygen concentrations than in the air condition. In the microscopic studies, it was confirmed that the local evaporation of carbon atoms due to oxidation appeared at the cathode side of the CNT structures under low current density, and the center area of CNT under high current density. Both types of damage morphologies induced by oxidation and EM were observed at the damaged CNT. The results showed the dominant damage mechanism alternated between oxidation and EM depending on current density under oxygen rich conditions.

Fabrication and Characterization of 4H-SiC 6kV Gate Turn-Off Thyristor

2012 ◽  
Vol 717-720 ◽  
pp. 1163-1166 ◽  
Author(s):  
Lei Lin ◽  
Jian Hui Zhao
Keyword(s):  
High Current Density ◽  
High Current ◽  
Initial Pulse ◽  
Large Area ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Pulse Testing ◽  
Blocking Voltage ◽  
Fabrication And Characterization

In this paper, we report a 0.1cm2 4H-SiC gate-turn-off (GTO) thyristor with 6 kV blocking voltage fabricated on a structure with a 60µm blocking layer. A relatively large area, high voltage 4H-SiC GTO that exhibits encouraging characteristic at the on- and off-states, and a low leakage current with 63% devices blocking 3kV or higher. Initial pulse testing result shows that the fabricated GTOs are capable of both high current density and high turn-off speed.

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